Nowadays, thanks to the extraordinary quick development of the information technologies, the Internet has also changed very much. Bigger and bigger sending rates are reachable on the networks, that makes easier the data flow from one host to another. The high speed environments require such congestion control algorithms what can meet the increased requirements. Since the conventional TCP is not able to do this, because it can not exploit the capacity of the available network, so new versions were invented, that can take over the role of the TCP Reno in today’s networks.
In my work, firstly I studied the major transport protocols which are suggested to the high speed network environments, and during my thesis I present those ones what are available in the current Linux kernel and are important (Scalable, BIC, CUBIC, HighSpeed, Westwood, Vegas). Then I got acquainted with the Dummynet network emulator program, what is used frequently during test network measurements, and I developed a laboratory environment, where the end points are computers with Linux operating systems running different TCP versions. So with the help of Dummynet I could make multifarious TCP communications on an arbitrary network. Next, I planned three concrete topologies and for those traffic situations. In these I could analyze the certain high speed TCP variants in the aspect of efficiency and fairness. Finally, I analyzed the results of the measurements.
I conclude my thesis by summarizing the results of the measurements and giving a short overview about the possibilities of future works.